WASHINGTON -- President Barack Obama said this week that "there is no immediate decision pending" on whether he will send more combat troops to Afghanistan, but members of Congress are already staking out their positions and bracing for a contentious debate.

Obama made his comments on September 16 following a White House meeting with Canadian Prime Minister Stephen Harper, who recently announced that Canadian military forces will leave Afghanistan in two years.

The president said a review of troop levels has been planned for several months, but only now, with a fresh assessment of the situation on the ground from U.S. and NATO commander General Stanley McChrystal in hand, could the review process begin.

"There is no immediate decision pending on resources, because one of the things that I'm absolutely clear about is you have to get the strategy right and then make determinations about resources," Obama said.

"You don't make determinations about resources, and certainly you don't make determinations about sending young men and women into battle, without having absolute clarity about what the strategy is going to be."

'Broad Consultation'

Obama sought to tamp down media speculation about what his decision will be by explaining how he plans to make it. "My determination is to get this right," he said. "And that means broad consultation not only inside the U.S. government, but also with our ISAF partners and our NATO allies. And I'm going to take a very deliberate process in making those decisions. "

When Obama took office in January, he ordered an additional 17,000 troops to Afghanistan. By November, there will be 68,000 U.S. troops there.

Obama may be keeping his cards close to his chest, but earlier this week the chairman of the Joint Chiefs of Staff, Admiral Mike Mullen, gave Congress a good indication of what the U.S. military is preparing to request.

"I do not know what additional resources General McChrystal may ask for. And I do not know what ration of training to combat units he really needs. We'll get to all of that in the coming weeks," Mullen said, testifying before the Senate Armed Services Committee.

"But I do believe that, having heard his views, and having great confidence in his leadership, a properly resourced counterinsurgency probably means more forces."

Democrats Against

The Senate Armed Services Committee is chaired by Carl Levin, the most powerful Democrat in Congress on military matters. Like many Congressional Democrats, Levin has come out against sending more troops to Afghanistan, saying he wants to see the United States accelerate its training of Afghan security forces.

Levin, who just returned from a trip to the war zone, wants the Afghan National Army increased to 240,000 troops and the Afghan police forces increased to 160,000 officers by 2012. Those levels are similar to current U.S. military planning, but the date is one year earlier.

Levin's equally powerful Democratic Senate colleague, Diane Feinstein, who chairs the Senate Select Intelligence Committee, has also come out against more troops, saying the mission is unclear and the United States and its NATO allies will never be able to build a democratic state in Afghanistan.

On the House side, Speaker Nancy Pelosi has warned that a request for more troops will run into stiff opposition from Democrats there and said she doesn't think there is "a great deal of support for sending more troops to Afghanistan in Congress or the rest of the country."

A CNN poll taken on September 11-13 found that opposition to the eight-year war is now at an all-time high, with 58 percent of Americans saying they oppose the U.S. military effort in Afghanistan and just 39 percent still supporting it.

That poll also found the lowest support among registered Democrats and the highest among Republicans (23 percent and 62 percent, respectively).

Opposition Backs Obama

That reflects the situation in Washington, where leading Republicans and defense hawks have spoken out in favor of the White House strategy in Afghanistan and urged Obama to ignore his critics.

Among the loudest voices are two prominent Republican senators, Obama's former presidential campaign rival John McCain of Arizona and Lindsay Graham of South Carolina.

Along with Senator Joseph Lieberman (Independent, Connecticut), the lawmakers wrote an opinion piece for the September 13 issue of "The Wall Street Journal" that said the war in Afghanistan is winnable and they are going "to stand with the president through the tough months ahead."

The piece was headlined, "Only Decisive Force Can Prevail in Afghanistan," and in it, the three senior lawmakers said success by the United States and its NATO allies would likely require "a significant increase in U.S. forces."

They wrote: "We recognize that a decision to increase the number of American troops in Afghanistan will be politically difficult here at home."

They went on to say: "More troops will not guarantee success in Afghanistan, but a failure to send them is a guarantee of failure. We have reached a seminal moment in our struggle against violent Islamist extremism, and we must commit the 'decisive force' that General McChrystal tells us carries the least risk of failure Obama was right when he said last year that, 'You don't muddle through the central front on terror.... You don't muddle through stamping out the Taliban.'"

Senator Levin plans to give his version of an opinion column on September 18, when he delivers a speech on the Senate floor explaining his reasons for opposing a troop increase.